A retrospective cohort analysis of cerclage in Twin pregnancies: perinatal outcomes & gestational age at delivery

Evidence on the effectiveness of cerclage in Twins is controversial. Data is limited to studies with small number of participants. Whether twin babies benefit from this intervention is unclear. Analysis of a large national sample may provide statistical power to support current recommendations. We analyze risk of perinatal complications after cerclage placement in Twin pregnancies using a large, national cohort. All U.S. Twin deliveries (2006-2013) with prior preterm birth/abortions (indicators of cervical insufficiency) were selected. Congenital anomalies, diabetes/hypertension conditions (common indications of delivery) & induction of labor cases were excluded. Demographics, obstetric interventions, perinatal complications, gestational age at delivery, & neonatal outcomes (low Apgar, assisted ventilation, NICU admission, surfact/antibiotic use, seizures) were analyzed. Cases with documented cerclage placement were compared to non-cerclage twin controls, matched by demographics & obstetric interventions (planned ratio 1:1). Binary analysis included MWU & χ2 test. Risks of preterm delivery and perinatal complications (outcome) was calculated by logistic regression according to cerclage placement (predictor), adjusted for confounders. Hazard ratios & Kaplan-Meier curves were obtained by cox regression. From ∼33 million deliveries, ∼1 million were twins (3.2%). After exclusion criteria and case:control matching, 2,023 cases & 2,023 controls were compared. Baseline data & outcomes are shown in the Table. Preterm delivery rates and complications were significantly higher in the cerclage group (p<0.05). Adjusted odds ratios showed no differences in perinatal complications (Figure). Survival curves also showed no differences in undelivered pregnancies in the cerclage vs. controls groups [log-rank p=0.405, HR (95%CI) = 0.9 (0.9 – 1.0)]. Our findings suggest that cerclage in twins (different than singletons) neither decreases preterm birth rates nor improves perinatal outcomes. Prospective studies are urgently needed to clarify these findings. However, given the limitations of performing such studies in this population; until then, data presented here may be considered for patient counseling and clinical practice.View Large Image Figure ViewerDownload Hi-res image Download (PPT)